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Discussion Starter #361
I'll have to double check, the problem is the belt length. If I recall the 901083 is actually 350 N-m. The width also matters but most are 30mm belts.
Honestly, the belts rarely break anymore if your car isn't putting out more torque than the belt limit. It's almost always the belt slips and wears out like a clutch.
I'll take a look tonight and send you a link to the website and you can review all the available belts.
 

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I'll have to double check, the problem is the belt length. If I recall the 901083 is actually 350 N-m. The width also matters but most are 30mm belts.
Honestly, the belts rarely break anymore if your car isn't putting out more torque than the belt limit. It's almost always the belt slips and wears out like a clutch.
I'll take a look tonight and send you a link to the website and you can review all the available belts.
I'd really appreciate the link @pboglio. Thanks brother. With the Nissan Almera 1.0T being around 300kg lighter than the juke, I'm sure the weight savings also lends itself to transmission durability. I see Raybestos also offers GPZ clutches for the JF015E and also clutch pack modules for the JF011E. Do you think this clutch upgrade would strengthen our CVT transmissions better? Of course after we've addressed other shortcomings like the oiling.

Regarding belt slippage, what are the steps one could take to prevent this?

Sorry for my ignorance. I come from a world of racing manuals and automatics. CVTs are really foreign to me.
 

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Discussion Starter #363
Here is the pushbelt catalog:


These are really good questions.

The Raybestos clutches are actually the OE clutches, no difference. I talked to them already about custom clutch discs for these CVT about 1 year ago, it's not going to happen. They make upgraded Carbon and Kevlar torque converter clutch discs, but not anything special for the forward/reverse clutch packs. I got around this by removing the wave spring in the clutch, modifying the pressure plate, and adding a 4th clutch disc to the clutch packs, while also modifying the clutch disc to make this work. This'll improve clutch pack torque by about 33%.

Yes, the weight savings plays a big role. I plan on running about 250 lb lighter to increase the durability at higher torque, so that's one way to do it but a very good way.

Oiling most you can do is run AMSOIL CVT fluid for high torque applications & replace the stock CVT filter often. Guys have good luck with external coolers. I have my own design water cooling setup that will handle the increased power levels I plan on running. So cooling helps to extend the oil life. I've heard Level10 modified the lubrication and cooling circuits in the valvebody and although it's possible to increase oil cooling flow rates, let's say by bumping the pressure from 75 psi to maybe 90 psi or something like this. I haven't tried it as for now I have too much going on with my CVT to attempt modifying everything, maybe later I'll try this.

Belt slippage........run AMSOIL CVT fluid and it will mostly kill the slippage problem if the CVT is in good working order. The coefficient of friction is 0.10 vs. .09 for NS-2/NS-3 fluid, so about an 11% increase. However, I believe the torque holding capacity is much higher based on my own testing. I did some modification to the pulley surfaces to increase the surface roughness, but decided the added belt wear wasn't worth it and went back to an OEM surface finish.

Also, Level10 had modified CVT pulley pressure to clamp harder with higher pulley pressures. Couple of members have done this and put down about 255 lb-ft of torque @ wheels on the dyno so it's effective. I have my own method electronically to do the same thing but that'll be tested when I get the car up and running. Ideally the TCM would be programmed to do this, but I'd have to have ECUTek attempt it and it's probably never going to happen.

The belt itself as I have stated are now almost unbreakable in the current generation F7 belt materials. I know guys have broken them, because they superheated or the main bearings or pulley's seized and snapped the belt. But most of the time the belt elements will wear out the "gripping" surfaces like a worn clutch. The key is to have the optimal oil flow, cooling, pressure, and driving technique.

Finally, the main reasons for all the reliability problems is the oil pump relief valve jamming. Sonnax have an effective relief valve upgrade that solves this problem.
 

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Thanks for the link @pboglio . Yeah I just checked.... 901083 and 901068 are different lengths... :( thats not very encouraging. I hope you don't mind another question: how does one go about determining the torque limits of the belt? by element width?

Are Level 10 still doing CVT upgrades? I thought they stopped doing it. I'd be interested in how you modify the clamping pressures. I am located in South East Asia. Sending my transmission to Level 10 is a bit difficult...

Regarding the raybestos clutches... well thats a downer. Raybestos claims their OE replacement clutches are better than and outperforms factory clutches. The GPZ clutch packs for the JF015E supposedly are a step up and performance orientated.



When I grow balls big enough, I'd probably buy myself a Posi-lock and a press, and open up the CVT transmission. Disassembly looks about as straight forward as taking apart a rotary engine. I have goals to make this econobox sedan run 12s... hahah
 

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Discussion Starter #365
Bosch state the torque limit on their belts, see the picture below. It's depending on the Belt width and band counts. The 901068 belt is a 24/9 belt, 24mm wide by 9 bands, 191.7mm length, F6 alloy material, B-type element. This belt is rated by Bosch at 150-200 N-m. This value can't be reliably exceeded.

You could try the 901090 belt, 24/9, 191.7mm length, F7 alloy material, C-Type element. This style has about a 10% higher grip force on the pulley due to the C-type belt element design. It also allows higher engine rpms as well. The F7 alloy is about 10% stronger. I'd rate this belt about 10% stronger and 10% higher torque clamp rating based on that, with an additional engine rpm capability. Torque probably is around +220 N-m. This is a fairly new belt as the higher P/N number denotes it's the latest design.

Yep, for the JF015E they have the clutch upgrade as you state which is cool. But for the JF011E they do not, it's the factory clutch disc material, basically OE supplier. So that would be a very effective upgrade, absolutely. The clutches burn up badly on these cars. That and AMSOIL fluid would make the transmission more durable.

For the higher clamping torque I designed an OP amp circuit that intercepts the CVT pressure transducer signal going to the ECM/TCM and reduces it's value. This tricks the computer into upping the pressure to the pulley, which increases it's torque holding capacity. It's a bit more sophisticated than a resistive circuit as there is a cut-in value I set at higher pressures to avoid affecting fuel economy. Anyway, it's something I might install later-on as it's not totally critical initially.

Level10 are not doing these transmissions anymore. I believe based on my experience talking with them that they only do the higher pressure, but can't confirm it. The higher pressure does nothing to reinforce the transmission, only prevents/delays it from slipping. As I've stated, I have no use for them since I already have fully upgraded the CVT myself and I know their reputation which wasn't good to begin with. Modifying the CVT isn't rocket science but it's a bit harder than building a motor. Definitely you need all the special tools, and some knowledge on how to press bearings and a few tricks. Lot's harder than building a motor actually since there are many places you can make big huge mistakes that are not obvious. I go into detail in this thread about those pitfalls, and what aftermarket parts to use and not to use.
189635
 

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Thanks @pboglio . Been a minute since I saw that pic. Totally forgot about it. 28/12 with over 400nm capacity looks delicious. But I don't think it will fit in my CVT?
 

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Discussion Starter #367
It won't fit your transmission, the belt length is all wrong.
 

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Discussion Starter #368 (Edited)
I should clarify, Exedy clutches are OEM tan version which I'm running. The Raybestos High Energy gray RCP96-256 is a moderate upgrade over the OE forward/reverse clutches.


I'm tearing the CVT down for the oil pump upgrade and clutch drum insert upgrade, so the clutches are coming out anyways. I'll probably place an order for (2) Raybestos sets so I can build up my custom (4) plate clutch setup.
 

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It won't fit your transmission, the belt length is all wrong.
Thanks for the clarification. I am in the midst of going thru your writing in the last 18 pages. You are really paving the way for future CVT developments and who knows your contribution might lead to CVT being used in mass market performance applications. I really hope you don't stop what you are doing.

I was following Fast Religion religiously (lmao) some time back and their 500hp target. But like you said they gave up too quickly. Its also a shame they took down their youtube.

The 901090 belt you recommended has been a real eye opener for me. Thanks for that. But its rating at +/- 220nm is quite a bit of a downer.

In the meantime I shall continue exploring options on the JF015E but perhaps a CVT8 swap may be better... who knows.
 

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Discussion Starter #370 (Edited)
Thanks. Hopefully if all this stuff works out there might be options for us AWD CVT owners who want a bit more power. I have most of the weak points identified and corrected but this I'd consider a Gen 1 upgrade. There are a couple more ideas for improvements I want to try but for this build it’ll be more than enough for my goals. In the future I’ll decide if I want to offer an upgraded transmission to members. The goal is to just get mine running and tested so I’m confident everything is working properly.

The FR build was interesting. My thoughts on that was was that 500 h.p. was never realistic. You almost have to tear down a trashed CVT to understand where and how it'll break, it's quite obvious. The rest is engineering analysis to understand what the torque limits are and that's where the R&D comes in. Basically, 350 N-m is the practical/reliable limit with every mod added to it. The belt is ultimately going to limit the entire transmission, mostly the belt slippage actually. With that kind of torque, 350 h.p. crank is totally doable while still not abusing the transmission. This build could greatly benefit from some TCM tuning, similar to the ECUTek Nissan GTR TCM programming, if it were available.

Anyway, the JF011e transmission has some serious internal design flaws and that had to be addressed first. I did some serious engineering analysis of the RE0F09b from the early CVT Nissan Maxima which was a 300 hp/ 260 lb-ft car with 3500 lb curb weight. A couple of my custom upgrades are based on that design architecture which is why I think 350 hp /257 lb-ft on the Juke @ 3100 lbs can be done reliably.

A CVT swap for your car would be challenging since the TCM would also have to be from that donor vehicle.
 

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Discussion Starter #371
Here's a cool video showing a Honda CVT manufacturing plant:

 

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Discussion Starter #372 (Edited)
Update:

I ordered and received the Raybestos RCP96-256 Clutch Module pack and R520010 single clutch disc. The module kit was $46 delivered from WIT which includes (3) Reverse friction discs and (3) forward discs, the single clutch disc is $11. I needed an extra disc for my custom forward drum. These are High Energy discs, the picture shows the standard OE tan discs from Exedy. The chart shows how much more durability the High Energy have over the stock Tan discs, which is about +67% life cycle fatigue improvement. The GPZ is not available for the JF011E, but it's also shown for comparison. So it can take the heat better, and although not shown it has a higher "energy load" capacity, meaning more torque capacity.

I'm showing my stock clutch packs from the teardown as reference here. This is what happens when you free rev in neutral to redline......you smoke the clutches. The factory run like .010" clutch pack clearance which means they are sitting "tight" in the drum. The plates were heat warped, blued, frictions were coned/warped and totally smoked/cooked. I'd put their torque holding capacity at about 210 wheel torque or 330 N-m. My dyno run with about 20k miles has these odd little wiggles in the dyno plot.....those are my clutch packs slipping and limiting torque. Over time this fries the clutches even though it doesn't really "felt" like they are slipping.

What people "think" is belt slip, isn't always so and in most cases isn't. Normally the belt slips in 1st gear launching or brake torquing, or if the fluid has air in it. Otherwise the forward clutches slip. This is kind of done on purpose because this protects the belt from over torque. Solution to that is: Raybestos High Energy forward/reverse clutch friction discs, AMSOIL CVT fluid, and adding a 4th clutch disc. How much extra torque capacity does this provide? Well, the stock clutches are good for 330 N-m on the AWD on average. I also confirmed the Raybestos clutch calculator puts the JF011E clutches at about 337 N-m using the 5.43" OD and 218 psi clutch apply pressures. Been my experience and all my datalogs and dyno run confirm no matter what I could do with boost levels I never could exceed 340 N-m maximum and typically more like 330-333 N-m. The High Energy friction discs are about +8-9% higher friction improvement (.125 vs .115 Cof), which improves torque capacity to 358 N-m. The AMSOIL fluid produces about +11% friction improvement (0.10 vs. .09 Cof), so that's 398 N-m. With a 4th clutch disc added that's another +33% improvement or 530 N-m or 390 lb-ft of torque. Obviously the CVT belt can't handle that much torque, but it's nice to have the extra capacity.

You can see how I'm not talking about increasing clutch pressure which is about 218 psi. Structurally this is dangerous to the JF011E clutch drum as it's already pushing it's fatigue limit. This can also blow-out the clutch apply piston. Mine is an upgraded SAP "High Blue" forward clutch piston but the point is higher pressure here is a mistake. The snap rings and pressure plates just start bending and it's not a workable solution. More friction is the answer.

As far as mileage, the stock clutches on a modified car might last to 60k miles if it's driven hard. According to Raybestos the gray High energy clutches would improve that +67% or 100,000 miles. So even if you aren't looking for more horsepower, the transmission durability goes way up. This isn't the only area the CVT is weak, but it's a huge part of why the typically fail.

The clutch pack assembled in the picture is the modified clutch pack with (4) discs installed vs. (3) factory style. The bottom wave cone spring was removed, the upper pressure plate was custom machined to remove a bit of material just under the snap ring to get the correct clearances, the remaining material was left intake for strength. The rebuilt clutch pack clearance is sitting at about .050" fully assembled now vs. .010" stock. The OE spec clearance is .047-.059", yet the factory run at .010". This'll greatly increase durability. I have to tear it back down to add the new Raybestos clutches but that' like 15 minutes worth of work. I also modify the lower friction disc and bend the (36) spline tabs upwards to grip the spline hub, this is the trick to how I made (4) clutches fit and transfer the torque. The spline hub that engages reverse gear would typically need to be lengthened to engage a 4th friction disc, but my little mod helps get around this limitation. I had looked at a custom machined spline hub but I'd have to remove the stock gear attached to it, drill thru the hardened gear, then custom billet machine the spline hub and screw the gear back onto it with locator shear dowel pins. I stopped at that point as I didn't want to do it due to the cost/difficulty but I've actually done this before at work for a custom application. But you understand WHY this transmission isn't really meant for an AWD setup, too many weakpoints. If I soften the boost curve this should help eliminate the issues I had with that part. The cone spring removal will make Part to Drive a bit more aggresive in the shift, otherwise no difference in driveability.

OK, so all that is sitting here waiting to go back in. Plus as I said I sourced the brand new JF011E oil pump from WIT tranmission, so I took the time to swap in the Sonnax hard anodized oil flow relief valve as well and that'll all go back in there.

What's left to do after these last 2.5 years? The final piece that is going out for custom machining is the "red" sleeve spline insert in that picture of the drum assembly. That 4340 piece of steel is going to reinforce the forward drum once the torque increases from the clutch improvements. That thing costs about $200 per piece to custom machine, but it's protecting a $3,000 transmission. It's about a 2 week lead-time to receive it then it get's glued in place. There is also some custom machining of the pulley input shaft inner bore to make clearance for this part. I'm doing that by hand with a carbide valve cutter and custom pilot guide. That steel insert then get's bonded to the forward drum with a tight slip fit which'll greatly improve the hub strength and durability.

Finally, the CVT belt which everyone thinks is the problem. Well, I'm now running the "revised" Bosch 901083 pushbelt. It looks the same as the stock 901066 but it's revised somehow. Possibly better metallurgy, not totally sure. Like I said, my stock pushbelt was worn out to hell and back but it never broke and would have kept running fine enough to daily drive if the forward drum didn't snap in half and blow out the torque converter clutch apply o-ring.

I've already discussed how I plan to bump up the pulley pressure using a custom designed OP Amp circuit, that'll be later on which is probably the last thing I need to worry about when I start cranking the boost up to higher levels. I'm not actually sure at what point the ECM/TCM stops adding pulley pressure as torques increases. This is an important point because most people don't realize the computer can feed in an extra boost of pressure if it detects a sudden pulley slippage. The oil pump has massive oil capacity in reserve to kick the pulley pressure upwards on demand for the belts and I've seen it on the datalogs. This trick only works IF the belt isn't already worn out though. Which is why if you start with a good cooling system upgrade and AMSOIL and don't launch or brake torque, the belt shouldn't slip unless you are doing something totally stupid.

Future stuff: Well, Raybestos also offer (4) different Torque converter clutch friction discs for the JF011E torque converter with a couple that are high performance. I'm trying to find a reliable source for converter rebuilds but the discs and replacement parts are readily available to order. I'm currently running a CVC JF011E reman torque converter (P/N DA30N) but they don't do custom builds. I believe they use the Raybestos "Carbon" clutch disc on their reman units but I cannot totally confirm it. It's more a nice to have but it would be cool to have a higher capacity converter in the CVT as well just to say it's upgraded.

Anyhow, we'll see how this comes along since I'm currently building the motor.


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189668
 

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It is amazing how many small parts have to work and hold power for everything to hold together.
 

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Discussion Starter #374
Mac,

Absolutely right, it's all got to come together.

Brain Storm and possible solution to a complete heavy duty JF011E CVT transmission:

I've been racking my brain on how to get the JF016E pulley (28-12 belt, P/N 901074) onto the JF011E for over 2 years now. That is basically the "heavy duty" pulley and pushbelt good for about 435 N-m (320 lb-ft). This comes on the 2015-2016 Juke AWD by the way from what I've researched. I was overthinking the problem basically. It appears at least visually that the JF016E pulley case might be a direct swap into the 2010-2014 Juke AWD JF011E transmission case, with some modifications listed below.

The JF016E has one minor hiccup in that the primary pulley speed sensor is relocated onto the pulley case with the primary reluctor wheel relocated on the pulley as well. Otherwise the pulley's & case "look" like a direct swap. This would require a primary speed sensor plug adapter to fit the existing harness as it's a different sensor now. What I figure is simply take the entire pulley, belt, end case assembly and direct swap that onto the JF011E. The bolt patterns visually match. The parking pawl bracket looks slightly redesigned but basically the same mechanically and location.The output gear count has to match, from memory the Juke has a 30 tooth and that is also available on the JF016E, gotta double check that.

The main problem is the transmission chassis mounting bracket bosses are missing.....little bit of a bummer. I suppose it's possible to design a CNC bracket mounted to the transmission case bolts to create a dedicated mounting bracket/plate. No welding would be advisable since the tolerances or super critical for the pulleys to fit back onto the trans case. These assemblies typically go for about $750 used, new belt is another $600-800 which would be highly recommended.

The first picture is the JF011E, note the skinny looking belt elements and thinner belt (30-10 band). The other picture is the JF016E with the "heavy duty" 28-12-band pushbelt designed for higher torque, higher rpms, & better belt traction. The pulley centerline dimensions would have to match bang on exact or they would never fit, but since they both use a 229.4 mm long pushbelt, I think they would fit right up. The belt is 2mm narrower, so I'm thinking the entire pulley set would have to get shimmed back +2mm using shims under the bearing race mounted in the end case, that's a guess though. Internally the factory JF016E has eliminated the little ball bearings for the pulley sheaves, and upgraded to roller pins which are meant for higher torque to avoid the problem of the ball bearings shearing in half and locking up the pulleys.

OK, this is for archival purposes. I will not even attempt this as I'm pretty much done with this car. I'm simply putting this up for reference. This would be a major R&D project but doable. IF the case mounting bolts and pulley stackups all fit internally, that's the trick. It would be cheaper to just buy a Gen2 Juke AWD which comes with the JF016E from the factory (310CM-3TX0C and 310CM-3TX0CRE) and just upgrade the clutches and all that business.

This might be good info for those who would want to Rally an AWD Juke or something like that. This would be an insane improvement as the belt/pulley would be good up to 319-320 lb-ft (435 N-m) according to the Nissan/Jatco engineers for the CVT8 JF016E.



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189680
 

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Well that is amazing and looks like a fairly simple unbolt rebolt with some minor modding. BUT would you be able to bump up the pulley pressure to make use of the better belt. So it doesnt slip.
 

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Discussion Starter #376
Mac,

Very good question. Firstly, that belt element design grips with a Cof of about 0.1 vs .09 for the stock belt. With the same pressure it can hold +11% more torque straight off the bat. The thicker elements also have more mass above the rocking pivot point and this helps to grip better at higher rpms too. But yes, you could bump the pulley pressure up and technically max the belt to 320 lb-ft. as Nissan rated the entire transmission at 435 N-m.
 

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Will the cvt manage that on its own by measuring slippage or would it require programming to tell it to tighten harder/sooner?

Extra durability is good, but improving launch on the cvt is a goal as well. Are we still in the same situation where visconti is the only one who has had any ability to touch anything cvt programming related? I don't think he ever actually divulged what he did, in detail. I have his cvt programming and based on my memory of stock vs his, I don't think he would be able to adjust what is needed to take advantage of this project. Is there anyone who can?
 

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Discussion Starter #378
The Nissan/ECUTek software keeps ramping the pressure with extra torque. I have a custom external OP Amp circuit that'll progressively boost that higher by about +5-8% more pressure but I've yet to test it on the car except on a simulator. Sonnax do something similar with their automatic transmission upgrades, plus they sometimes have to add a stiffer spring in the pressure regulating valve in the valvebody. Almost certainly this is what Level 10 did back in the day as they've done it on their other customer's cars.

Visconti is modifying the torque tables in the ECM. I haven't seen them but if it's similar to the Hondata Torque tables it basically just increases the limits. The TCM controls the pressure and no one has access to those tables that I've seen. The pressure does ramp higher with more torque, but only for the pulley belt. The forwary clutch is maxxed at 213 psi regardless, which is one of the main things that slips on these cars.

I've looked at the ECUTek GTR TCM and you can increase pressure, shift points, etc.

The only company that could attempt it is ECUTek themselves. I'm not holding my breath as it's been almost 10 years since I got my ECUTek tune and they haven't progressed much further than what they have now for the Juke. John barely communicates, so I haven't asked nor do I care to do so.
 

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Discussion Starter #379
OK, so I dry tested these new Raybestos High Energy clutches just to see how good they are by clamping a couple of them together and trying to twist them by hand. I know they will normally be soaked in CVT oil, but it's a comparative test.

The difference in dry friction is absolutely massive, it's like a visegrip, they just don't slip. Having said that, these supposedly are "smoother" shifting on dynamic clutches. The Exedy Tan OE clutches slip when you press on them and twist, there is a reason they burnup on the JF011E all the time. I was thinking maybe +10-15% more improvement, honestly it feels like +50%. The Raybestos just clamp like velcro. Imagine running stock brake pads, then slapping in some Hawk Track pads......that kind of difference.

Can't wait to get these mounted up on the forward clutch drum and reverse drum. Anyway, very very cool product and I wasn't expecting them to be this pronounced of a difference. I think these are similar compounds to their HT clutches but without the fancy pad-like clutch face patterns. For some reason they don't promote these as much as the HT style, even though I believe they are the same/similar compounds. I could easily see these clutches holding 300 lb-ft no problem on a stock CVT. On my setup with (4) clutches more like +400 lb-ft if the pushbelt could even handle it.
 

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The description of the 213 psi clutch pressure meshes (no pun intended) pretty well with real life description of the cvt being a dog. It has no problem revving up, apparently no real problem hooking up internally, but the clutch is just not grabbing in order to put down the power.

Seems like just doing the raybestos clutches could at least put the power on the road, at the cost of moving the stress up the line. Basically taking away it's own built-in protection and leaving it up to the driver to decide how hard they want to push it, knowing that it could/will wear the cvt internals faster, burn your cvt fluid faster, etc. But at least it won't dog anymore... until it breaks something upstream?

And it would probably be the first time a performance clutch upgrade doesn't cause whiplash from hard shifting or noisy chatter!
 
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